Type Casting (or)type conversion:

Type casting is a process to convert one data type to another. It makes the variable compatible temporarily. We often encounter situations where there is a need to store a value of one type into a variable of another type. In such situations, we must cast the value to be stored by preceding it with the type name in parentheses. Casting is often necessary when a method returns a type different than the one we require.

Four integer types can be cast to any other type except boolean. Casting into a smaller type may result in a loss of data. Similarly, the float and double can be cast to any other type except boolean. Again, casting to smaller type can result in a loss of data. Casting a floating point value to an integer will result in a loss of the fractional part. If the following order is used for type casting, it guarantees in no loss of information.

byte à char à short à int à long à float à double

for example

• byte value can be converted to int or double

• int value can be converted to long or float

The syntax for casting is: type variable1 = (type) variable2;

Type casting can be of two types:

Implicit type Casting (Automatic Conversion): when constants and variables of different types are mixed in an expression they are converted to the same type. This conversion is done implicitly by the C compiler. The C compiler converts all the operands to the type of the largest operand. For example if an expression involves int and float, int type gets converted to float type.

Example:

float x=32;

The value of the x will be ’32.0’, because of implicit conversion of value from int to float

Explicit type Casting: if a user forcefully changes the data type into other allowable data type it is said to be explicit type casting.

Example:

int to float:

float x;

x=5/2 /* value of x will be 2.0 */

x=(float)5/2; /* value of x will be 2.5 */

float to int:

int x;

x= 3.2 /* causes error */

x=(int)3.2 /* x will be 3 */